CRP Materials Recovery Facility (MRF) Processing Technologies 1 — Questions and Answers
Question 1: What is the primary function of an eddy current separator in a MRF?
- To separate non-ferrous metals (especially aluminum) from the material stream using an electromagnetic field (Correct answer)
- To sort paper from plastic using air currents
- To remove moisture from collected materials
- To detect and remove hazardous materials
Correct answer: To separate non-ferrous metals (especially aluminum) from the material stream using an electromagnetic field
Eddy current separators create a rapidly changing magnetic field that induces electrical currents in non-ferrous metals, repelling them off the conveyor for recovery.
Question 2: What does an 'optical sorter' do in a modern single-stream MRF?
- Uses near-infrared (NIR) or visible-light sensors to identify and air-jet eject specific materials by type (Correct answer)
- Sorts materials by color using human visual inspection
- Weighs materials on a conveyor for billing purposes
- Detects metals using X-ray technology
Correct answer: Uses near-infrared (NIR) or visible-light sensors to identify and air-jet eject specific materials by type
Optical sorters analyze the spectral signature of materials passing on a belt and use bursts of air to eject target materials into separate chutes, enabling high-speed automated sorting.
Question 3: What is the purpose of a 'trommel screen' in MRF processing?
- To separate materials by size using a rotating cylindrical screen with holes (Correct answer)
- To shred oversized materials into smaller pieces
- To wash and clean contaminated recyclables
- To separate heavy from light materials using water
Correct answer: To separate materials by size using a rotating cylindrical screen with holes
Trommel screens use rotation and gravity to sort materials by size — smaller items fall through screen holes while larger items are carried out the end, enabling effective size-based separation.
Question 4: What is a 'disc screen' (OCC screen) used for at the beginning of a MRF line?
- To separate large flat cardboard (OCC) from smaller mixed materials using rotating star-shaped discs (Correct answer)
- To shred incoming cardboard bales
- To remove glass from the incoming stream
- To detect metal contamination in cardboard
Correct answer: To separate large flat cardboard (OCC) from smaller mixed materials using rotating star-shaped discs
Disc screens at the front of a MRF line use rotating discs to screen out large corrugated cardboard (OCC) at the start, preventing it from jamming downstream equipment.
Question 5: What is a 'glass breaker screen' designed to do in single-stream MRF processing?
- Intentionally break glass into small fragments that fall through screen openings, separating glass from other recyclables (Correct answer)
- Protect workers from broken glass hazards
- Prevent glass from entering the paper stream
- Sort glass by color before processing
Correct answer: Intentionally break glass into small fragments that fall through screen openings, separating glass from other recyclables
Glass breaker screens crush glass containers early in the process, causing fragments to sieve through screen openings and separate from containers, films, and paper that stay on top.
Question 6: What does 'throughput' mean for a Materials Recovery Facility?
- The volume or weight of material processed per unit of time, typically expressed as tons per hour (Correct answer)
- The total number of bales produced per day
- The percentage of material that is successfully recovered
- The number of collection trucks serviced per shift
Correct answer: The volume or weight of material processed per unit of time, typically expressed as tons per hour
Throughput measures MRF processing capacity (e.g., 25 tons/hour), which determines the facility's ability to handle contracted material volumes without creating backlogs.
CRP Materials Recovery Facility (MRF) Processing Technologies 1
What is the primary function of an eddy current separator in a MRF?